[Bajszi]

Hi guys,

This is my first post here. I did some search around the forum, but I couldn't find a similar topic so I decided to open one. My concern is the high exhaust temperature on my bike. I started measuring it because last in the season I melted my Givi side box.

I installed a temp sensor right at the end of my exhaust pipe into the exhaust gas stream and my brother was sitting in the back with a multimeter, and checking the temps. These are the measurements:

3000 RPM: 250 C / 480 F
4000 RPM: 280 C / 535 F
5000 RPM: 390 C / 735 F
6000 RPM: 450 C / 840 F
6500 RPM: 490 C / 915 F
8000 RPM: 620 C / 1,150 F
9000 RPM: 650 C / 1,200 F

It's a 2004 Suzuki Bandit 1200S with a Yoshimura RS-3 Slip on exhaust and Level 1 dyno kit.

In my opinion, the bike burns rich, it's very stinky in the back and sometimes I can also smell the fumes on my clothes after a long ride. But if it's rich, exhaust gas shouldn't be high, it should be cooler I think.

Do you guys have any suggestions?

Thank you in advance!

Bajszi

 

[hogcowboy]

Hi guys,

This is my first post here. I did some search around the forum, but I couldn't find a similar topic so I decided to open one. My concern is the high exhaust temperature on my bike. I started measuring it because last in the season I melted my Givi side box.

I installed a temp sensor right at the end of my exhaust pipe into the exhaust gas stream and my brother was sitting in the back with a multimeter, and checking the temps. These are the measurements:

3000 RPM: 250 C / 480 F
4000 RPM: 280 C / 535 F
5000 RPM: 390 C / 735 F
6000 RPM: 450 C / 840 F
6500 RPM: 490 C / 915 F
8000 RPM: 620 C / 1,150 F
9000 RPM: 650 C / 1,200 F

It's a 2004 Suzuki Bandit 1200S with a Yoshimura RS-3 Slip on exhaust and Level 1 dyno kit.

In my opinion, the bike burns rich, it's very stinky in the back and sometimes I can also smell the fumes on my clothes after a long ride. But if it's rich, exhaust gas shouldn't be high, it should be cooler I think.

Do you guys have any suggestions?

Thank you in advance!

Bajszi

Does Level 1 dyno kit mean you are using a wired tuning device of some kind? If so, which device and are there other maps you can load into that device? Where did you get it, Fuelmoto or Dynojet or your dealer. I'm at first thinking you might have the incorrect map for your addons. Did you do this or your dealer or someone else? Others will be able to help much more than I but just trying to get more info so they can.

 

[Porky]

Real rich doesn't mean cooler temps, especially if some of the fuel is ending up unburned in the exhaust.:surprise:

I had the same bike ( same exhaust as you have) and a Yoshimura slip-on doesn't require a rejetting Dyno kit at all as it won't run lean with just the slip-on unless you foolishly replaced the stock air box with 4 pod filters.:sad:

I have found that a lot of those "KITS" aren't worth beans and almost all of them make the scoot run super rich.lain:

I rode mine in Southern California very hot temps in stop and go Interstate traffic and it never even felt hot.:wink2:

Sam:nerd:

 

[FlipFlop]

Yeah there is a lot of mis info out there on bikes there is a case by case on each model. Yours I really dont know anything about except that I heard that they are awesome bikes. When I first got into the Ninja ex500 model I hated them nothing made sense. They ran rich and could not put performance pods on them, then I joined a forum after making a lot of vey expensive mistakes and trial and error stuff. It later became one of my favorite bikes. With CV carbs they have to be tuned to the bike if you have changed anything in the dynamics of how they run. (Pods, k&n filter, jetting, full system exhaust, sometimes even slip ons, or even type of fuel, modifications to the airbox). Putting the bike on a dyno can help getting it tuned perfectly, there are exceptions. Those exceptions should be discussed with someone other than me however because that bike specifically have done no research on. At the same,time those temps coming out your tip are not what you measure, you measure multiple things and header temp is one of them, but not just that. Give your brother a break from his reading and check out a bandit forum and see what others have done my guess either the carbs need to be freshened or someones improper jetting undone.

 

[Bajszi]

Thanks guys for all the replies!

hogcowboy: This is the DynoJet I have in it: [Sorry, I couldn't use link, but google will bring it up easy!]
It's the Stage 1 and I believe it is just parts changes in the carb. The previous owner did it (not sure if it was done in a shop or by himself).

Porky: I fly planes. There, we have a lever called mixture, which changes the air to fuel mix ratio. We need this because of the altitude changes. There we try to find the peak temp with the mixture once en route and depends on the plane/pilot, we either run it rich of peak or lean of peak. The more fuel we add to the mixture, the cooler the cylinder head and exhaust gas get. I know those systems might be different, but they are the same 4 stroke engines. This is where my thought came from.

Aphrodite: I also have a k&n filter installed with the stage 1 DynoJet and the Yoshimura exhaust. I didn't change any of these, it was the previous owner.

My aim is to make the bike into a stage where it's enjoyable for longer rides but I also wouldn't mind some power in case I want to enjoy the sport side of this bike. Of course, touring is more important for this. Do you guys think I should find a shop where they can fix these issues, or is it possible to do it in my garage? I do lots of vehicle maintenance and DIY jobs, but I have never done any engine related tuning.

Cheers

 

[FlipFlop]

You can do it in your garage. My thought is to go back to stock carb set up. Betcha, that bike does not need those things. Get it set up the find someone that would test its tune on a dyno. I am a fan on K&N but only after all else is correct.

 

[Eye_m_no_angel]

hogcowboy: This is the DynoJet I have in it: [Sorry, I couldn't use link, but google will bring it up easy!]
It's the Stage 1 and I believe it is just parts changes in the carb. The previous owner did it (not sure if it was done in a shop or by himself).

What that means is someone changed the jets in the carburetors.

Have you tried reading the plugs?

 

[Bajszi]

I just went through the DynoJet parts (remainings in the box) and it seems parts are used, but none of the main jets. I thought that is one of the main parts of the upgrade. This seems to be a bigger mess than I anticipated.

Eye_m_no_angel, what do you mean on reading the plugs?

 

[Bajszi]

What that means is someone changed the jets in the carburetors.

Have you tried reading the plugs?

I googled it, yea I know this method but it didn't ring a bell when you mentioned it. I haven't checked the plugs for a while, but yea I should do it. :smile:

I'll get back to you guys with the result.

 

[Bajszi]

So here is what I have:

I removed and replaced all 4 spark plugs. It seems to me they have a little carbon fouling sign on them, but I don't think they are too bad. But this is where you guys can give me any inputs. The plugs were in the socket really loose. I torqued the new ones to 11 Nm (based on service manual) and that felt good. The old ones came out nearly with my bare hand.

I did some inspection camera photos as well on cylinder but unfortunately, it's an old one, and pic quality is not great.

Last couple pictures are showing how I measured the exhaust temp.

 

[Bajszi]

I couldn't post pic in the same comment, so here they are:

 

[Porky]

To me, as a engine builder and tuner, your plugs look fantastic.

With stock stuff, the plugs would be almost white or a very light grey/ bone color.

Your piston crowns look alright also, especially for the amount of miles. Running heavy doses of Seafoam in maybe 5 tanks of gas may clear most of that carbon out.

Please do something about your exhaust hanger

Sam

 

[FlipFlop]

What is the gap on them plugs? They look very open, however definately not rich though. If anything, lean. But the shots into the cylinders seems to tell a slightly different story... Humn...

 

[Bajszi]

To me, as a engine builder and tuner, your plugs look fantastic.

With stock stuff, the plugs would be almost white or a very light grey/ bone color.

Your piston crowns look alright also, especially for the amount of miles. Running heavy doses of Seafoam in maybe 5 tanks of gas may clear most of that carbon out.

Please do something about your exhaust hanger

Sam

Thanks for the feedback Sam! So I'm guessing the mixture is in a good state? I did run a Seafoam through the bike, it was running a little rough at the beginning of this season. I only put it in the engine oil and into the fuel. Is it necessary to spray it into the air intake as well? I was thinking it is not that important with the carb engines as the fuel and air mixes before it enters the engine. Any advice on that?

Do you mean the copper wire as my "exhaust hanger"?

 

[Bajszi]

What is the gap on them plugs? They look very open, however definately not rich though. If anything, lean. But the shots into the cylinders seems to tell a slightly different story... Humn...

The new ones were between 0.025-0.027 and it's good between 0.024 and 0.028 for this bike. I haven't measured the old ones, but I will do it later. So if it's lean, that might tell why it's so hot. But then I'm not sure why it smells so rich and stinky. Plus when decelerating fast, the exhaust backfires a bit. It was worse with the old plugs, but it still does it a little with the new ones. I'm not sure if this tells anything or if it's normal.

 

[Porky]

"Is it necessary to spray it into the air intake as well?" Quote

Next time you get a chance, get a can of GUM OUT and spray it into the intake bores of the carb and let it soak a while. Then start the engine up and at maybe 3,000 rpm's or so, spray some more!

Sam:grin:

 

[Eye_m_no_angel]

The plugs look okay to me too, for old plugs, but the only thing you can tell from them is a general idea over the life of that plug. After you've ridden 50-100 miles, with as much at highway speeds as you can, pull out the new plugs and look at THEM. That will give you an idea of what's happening right now.

 

[hogcowboy]

The plugs look good to me also but why just 3 cylinder shots and 4 plugs? I was trying to figure out if it was a 3 cylinder with an odd plug thrown in or a 4. This smell you complain about might just be venting off pressure or the brand of fuel even. Some fuel does smell more than others depending on additives. Is this outside or in a garage? If in a garage just leave it outside until it vents off then bring it in.

 

[Porky]

A Suzuki 1200S has a 4 cylinder, in line, carbed engine. It has ABS. It is a more relaxed, upright, very high performance bike, just slightly less powerful than the 'Superbikes' of the time.

Sam

 

[Bajszi]

The plugs look good to me also but why just 3 cylinder shots and 4 plugs? I was trying to figure out if it was a 3 cylinder with an odd plug thrown in or a 4. This smell you complain about might just be venting off pressure or the brand of fuel even. Some fuel does smell more than others depending on additives. Is this outside or in a garage? If in a garage just leave it outside until it vents off then bring it in.

Sorry, I missed a word there, I only did the camera on one cylinder, on #4 . Quality wasn't good, so I uploaded 3 pictures. I usually store it inside the garage, but I don't put it in right away. Sometimes I can smell the exhaust on my clothes after a long ride, that's what bothers me.